1) Field of the Invention
The present invention relates to a door lock system for vehicles and has a lock mechanism housed in a housing and switches the lock mechanism between an unlocked state and a locked state by a driving force from the outside of this housing.
2) Description of the Related Art
In cars, a door lock system is generally provided between an outside handle and an inside handle provided in a door and a latch mechanism. The latch mechanism has a latch and a ratchet. When the door is closed, the latch mechanism engages with a striker on the vehicle main body side via the latch and the ratchet maintains the engagement between the latch and the striker to maintain the closed state of the door to the vehicle main body. The door lock system has a lock mechanism that is switched between an unlocked state and a locked state due to operation with a key of a key cylinder provided on the outdoor side of the door or operations on an inside lock button provided on the indoor side of the door. The lock mechanism and the key cylinder are linked to each other and the lock mechanism and the inside lock button are linked to each other by link units such as links or wires.
When the lock mechanism is unlocked, this door lock system enables and transmits a door opening operation of the outside handle or the inside handle to the ratchet, and when the ratchet engages with the latch, the lock mechanism releases the engagement of the ratchet with the latch. As a result, the engaged state between the latch and the striker is also released, and it becomes possible to open the door. On the other hand, the door lock system disables at least a door opening operation of the outside handle and does not transmit it to the ratchet when the lock mechanism is locked. As a result, the latch and the striker are maintained in their engaged state even when the outside handle is operated, and it becomes possible to lock the vehicle.
Conventionally, a door lock system is known that houses a latch mechanism in a first housing (latch mechanism housing) and has a lock mechanism housed in a second housing (lock mechanism housing) and assembles the first housing and the second housing to the door while they are assembled and integrated. On the upper portion of this conventional door lock system, a key lever which the front end of a rod projecting from the key cylinder fits in a torque transmittable manner is arranged. The conventional door lock system has seizing units in both housings, in which a guide projection is provided on either one of the housings, a guide groove that fits the guide projection is provided in the other housing, and the guide projection and the guide groove engages with each other to prevent coming out (for example, Japanese Published Unexamined Patent Application No. 2002-129811).
On the other hand, a door lock system is known that has a courtesy switch that comes into abrasive contact with a cam surface formed on the outer circumferential surface of the latch and outputs a signal when the latch is opened or switched from a half-latching state to a full-latching state (for example, Japanese Published Examined Patent Application No. S61-49471). According to this door lock system, when the latch is opened or switched from a half-latching state to a full-latching state, the door is judged as closed and an indoor lamp provided inside the vehicle is turned off, and when the latch is opened or half-latched, the door is judged as half-shut or opened and the indoor lamp provided inside the vehicle is turned on.
However, with conventional door lock systems, the key lever is disposed on the upper side, so that rain water or the like adhering to the key cylinder or a window glass of the door reaches the key lever through the rod and enters into the door lock system. The rain water reaches the mechanisms of the door lock system positioned lower than the key lever and causes the mechanisms to malfunction.
In the conventional door lock system, the guide groove is a member that the guide projection fits in a slidable manner. Moreover, the seizing unit is formed by providing a seizing shaft in the second housing and a seizing groove that fits the seizing shaft in the first housing. The seizing groove includes an engaging hole that fits the seizing shaft and a narrowed portion having a width slightly smaller than the diameter of the seizing shaft. Namely, the guide projection is slid and fit to the guide groove and the seizing groove is fit to the seizing shaft in the diameter direction, whereby the first housing and the second housing are integrated so as not to come out of each other. However, when the seizing groove is fitted to the seizing shaft, it is required that the narrowed portion of the seizing groove is strongly pushed so as to pass over the diameter of the seizing shaft to fit the engaging hole to the seizing shaft. As a result, the assembly for integrating the first housing and the second housing requires a strong force, and this leads to low efficiency in assembly.
Moreover, in the door lock system that is attached to a door while the latch mechanism housing which houses a latch mechanism and the lock mechanism housing which houses a lock mechanism are assembled and integrated, a signal cable connected to a courtesy switch must be wired outside the door lock system from the inside of the latch mechanism housing, so that signal cable wiring is difficult.